3-(4-pyridyl)-4-(2-hydroxyphenyl) pyrazole derivatives

ABSTRACT

Pyrazole derivatives of the general formula:   WHEREIN R1 and R2 are each hydrogen, methyl, ethyl, n-propyl, isopropyl, or n-butyl and X is hydrogen, hydroxy, methyl, methoxy, chlorine, or bromine, and their acid addition salts, have anti-viral activity against both RNA and DNA viruses such as myxoviruses, adenoviruses, rhinoviruses, and various viruses of the Herpes group based on known testing procedures on experimental animals and human embryonic lung cultures. The compounds are active when administered orally or topically. They may be prepared by heating hydrazine hydrate or an alkyl hydrazine with a 3-benzofuryl ketone.   D R A W I N G

United States Patent Binon et al.

[54] 3-(4-PYRIDYL)-4-(2-HYDROXYPHENYL) PYRAZOLE DERIVATIVES [72] Inventors: Fernand Binon, Brabant, Belgium; Jay

Morton Beller, Philadelphia, Pa. [73] Assignee: Richankon-Merrell, Inc., New York, NY. 22 Filed: Sept. 24, 1969 [21] Appl. No.: 860,789

[30] Foreign Application Priority Data Oct. 4, 1968 Great Britain ..47,29 7/68 [52] US. Cl. ..260/296 R, 260/295 F, 260/2955 B,

- 424/266 [51] Int. Cl. ..C07d 31/42 5 8] Field of Search ..260/296 R [56] References Cited OTHER PUBLICATIONS Antibiotic News, Vol. 5, No. 9, October 1968.

The Merck Manual, Eleventh Edition, pp. 1268- 1269, (1966) RS 356- M524 C23. Frobisher-Fundamentals of Microbiology Saunders [151 3,678,063 [451 July 18,1972

Publishers, Second Edition, pp. 71, 79 and 80, 1962 OR 46 F 76.

Primary Examiner-Alan L. Rotman Attorney-Harvey W. Edelblute [57] ABSTRACT Pyrazole derivatives of the general formula:

10 Claims, No Drawings 3-(4-PYRIDYL)-4-(Z-HYDROXYPHENYL) PYRAZOLE DERIVATIVES This invention relates to pyrazole derivatives having a polyvalent antiviral action, to pharmaceutical compositions containing said derivatives and to the therapeutic use thereof. The invention also relates to a process for preparing the pyrazole derivatives.

It has been found that there is a class of pyrazole derivatives the members of which possess the unusual and unexpected property of exerting a polyvalent antiviral action, in that they have been found to be effective against both RNA and DNA viruses and especially against myxovirus, adenovirus, rhinoviruses and various viruses of the Herpes group based on known testing procedures on experimental animals and human embryonic lung cultures. It has also been observed that compounds in this class tend to exert an influence upon cellular proliferation and metabolism.

This class of pyrazole derivatives can be represented by the wherein. R and R which may be the same ordifferent, represent hydrogen, methyl, ethyl, n-propyl, isopropyl or nbutyl; and X represents hydrogen, hydroxy, methyl, methoxy, chlorine or bromine.

Examples of compounds falling within the definition of formula I are 3-(4-pyridyl)-4-(2-hydroxyphenyl) -5-ethylpyrazole, its S-methyl, S-n-propyl, 5-isorpopyl and S-n-butyl homologues, 3-( 4-pyridyl)4-( 2-hydroxy-5-methoxyphenyl)-5- methylpyrazole, 2-methyl-3-(4-pryidyl)-4-( 2-hydroxyphenyl)- S-ethylpyrazole and its 2-isopropyl and 2-n-butyl homologues.

The pyrazole derivatives represented by formula I form acid addition salts with either inorganic or organic acids, for exam ple hydrochloric acid and oxalic acid, and hence the pharmaceutically acceptable acid addition salts of the compounds of formula I, which, as would be expected, also have the aforementioned polyvalent antiviral action, may be employed if desired instead of the free base.

Thus in accordance with one aspect of the present invention there is provided a pharmaceutical composition for prophylactic or curative use against RNA and DNA viruses, the composition being in a form suitable for topical or in tranasal administration and comprising as an essential active ingredient a pyrazole derivative represented by formula I, or a pharmaceutically acceptable acid addition salt thereof, and a pharmaceutical carrier therefor.

The pharmaceutical composition can be in the form of, for example, an ointment for topical application or a solution or suspension for intranasal administration and hence the pharmaceutical carrier may be, for example, an ointment base,

. distilled water, or an emulsifying medium containing one or more emulsifying agents. The composition may contain, for example, from 1 to 20 percent, preferably 1 to percent, by weight of theactive ingredient, the actual amount varying ac cording to the mode of administration employed and to whether the composition is to' be employed for curative or prophylactic use. 7

The pyrazole derivatives represented by formula I can be prepared in accordance with the invention by the use of a known procedure, such as for example, by heating with wherein R and X have the same meanings as in formula I, in accordance with the method described in Bull. Soc. Chim. Belg. 73, 459-482, 1964, and isolating the corresponding pyrazole derivative which forms. The reactants are preferably heated in an inert organic medium, for example methanol ethanol or isopropanol.

The starting-products represented by formula II wherein R, is other than hydrogen can be prepared, forexample, by reacting the hydrochloride of isonicotinoyl chloride with an appropriate 2-alkyl-benzofuran optionally substituted in the 5- position, by the method described in Chimie Therapeutique 2, 119, 1967, whilst the starting-products in which R is hydrogen can be prepared in a similar manner using an appropriate benzofuran, by the method described in Bull. Soc. Chim. France 1952, 1,056-1060.

The acid addition salts of the compounds of formula I can be prepared by treatment of the free base with an appropriate acid usually in the presence of an organic medium, for example an alcohol.

As mentioned above, the pyrazole derivatives represented by formula I have been found to possess a polyvalent antiviral action. Biological tests have been carried out with a view to determining the polyvalent antiviral activity of the compounds of formula I with respect to certain viruses of the RNA and DNA groups. The viruses were given in lethal dilutions made up of multiples of the concentration required to kill 50 percent of untreated animals LD As regards the RNA class of virus, three types of test (Tests Nos. 1, 2 and 3) were performed on mice using various lnfluenza viruses.

Test No. l (Mouse-Survival Test) The mice were first divided into two groups. The animals of one group were given, either by intraperitoneal (IP) or by oral (PO) route, the compound to be tested, suspended in 0.25 per cent of carboxymethylcellulose. One hour later they were infected with a dilution of the virus by aerosol. Further doses of the compound to be tested, of the same concentration as the first, were then given by the same route, 3, 24, 48 and 72 hours after infection. The animals of the other group, which constituted the control group, were infected in the same manner as the treated animals but did not receive any compound of the invention.

In the course of the test, which lasted fifteen days, the following data were registered:

a. The Mean Day of Death (MDD) expressed in days for both the treated and controlgroups.

b. The ratio of the MDD of treated animals to the MDD of control animals giving the Survival Index (S1). The SI was considered significant if it exceeded 1.24..

c. The percentage of treated animals surviving at the end of the test.

The compounds of the invention employed in the first series of trials were 3-(4-pyridyl)-4-( 2-hydroxyphenyl)-5-ethylpyrazole (Compound A), its S-methyl (Compound B), 5-npropyl (Compound C), 5-isopropyl(Compound D) and 5-nbutyl (Compound E) homologues, 3-(4-pyridyl)-4-(2-hydroxy-S-methoxyphenyl)-5-methylpyrazole (Compound F), 2- methyl-3-( 4-pyridyl )-4-( Z-hydroxyphenyl)-5-ethhy-pyrazole (Compound G) and its 2-isopropyl (Compound H) and 2-nbutyl (Compound I) homologues. All these compounds can of course exist in the form of a pharmaceutically acceptable acid addition salt thereof.

The following results were registered:

hydraiine hydrate or with an appropriate alkyl hydrazine, a 3- Survival benzofuryl ketone represented by the general formula: Vlms Dose Compound Route mg/kg Percent S.l. Multiples of LD,

X C A IP 500 37.5 1 7| 25 IP 50 O 1.37 25 R1 PO 500 33.3 1.71 56 o 11 5 IP 500 0 1.29 56 IP O 1.36 13 F II 500 0 1.29 28 H IP 500 30 1.91 21 IP 5 O 1.32 21 In another series of trials with compounds A and D but involving other Influenza viruses, the following results were obtained:

Virus Dose Dose Compound Route Virus Multiples Survival mg/kg of LD Percent 8.1. 50011 .lap 305 32 60 2.04 50 IP 32 10 1.34 500 P0 3.2 66 1.43 50 P0 3.2 60 1.43 5 IP 20 20 1.34 5001P Maryland 79 10 1.47 500 PO B 79 12 1.52 A 500 IP Swine A 14 50 1.52 D 500 P0 Jap 305 15 100 2.12 50 P0 15 30 1.31 50011 22 70 2.16

Taking 1.24 as the minimum significant Survival Index figure, the above Tables show that the compounds so tested were effective in prolonging the survival time of mice exposed to lethal dilutions of various Influenza viruses.

TEST NO. 2(48-I-IOUR MOUSE TEST This test was undertaken for the purpose of studying the effects of the compounds of the invention on different viruses during the early stages of the virus growth cycle in the mouse.

The mice were divided into three groups. The first two groups received a dose of the compound to be tested, one group by intraperitoneal (1P) route and the other by oral (PO) route. One hour later, all three groups were infected with a dilution of the virus by aerosol. Further doses of the compound to be tested, of the same concentration as the first, were then given to the first two groups by the same route 3 hours and 24 hours after infection. The third, untreated, group constituted the control group. Forty-eight hours after infection the treated groups were sacrificed simultaneously with the control group. The lungs from each group were removed, pooled separately by group, and ground in a hydrolysate of casein to form three 10 percent homogenates. Two series of dilution, in which each dilution was one tenth of the concentration of the preceding dilution, were prepared from the homogenates obtained from the treated animals. These dilutions were subsequently injected (0.2 ml/egg) into 1 l-day-old embryonated chicken eggs for titration of the egg infectivity of the virus contained in the mouse lung material. Six eggs were infected with each dilution of virus. After incubation for 48 hours at 37 C. the eggs were chilled and the allantoic fluid from the eggs collected. A haemagglutination pattern was obtained by adding 0.5 ml of a fresh 0.5 percent suspension of chick erythrocytes to an equal volume of allantoic fluid from each egg. The titre at which the 50 percent endpoint of egg infectivity (ElD occurred was calculated from the results of the haemagglutination test. These results were compared with that obtained by the same process using lung material from the control animals. A one-log reduction in ElD as compared with the control figure was considered significant.

The compound of the invention used in this test was 3-(4- pyridy1)-4-(2-hydroxyphenyl)-5-ethylpyrazole. The results obtained with this compound against the different viruses em ployed are given hereunder:

Compound Log Virus dose Virus Reductions as Multiples Dose compared Route of LD,,,

mg/kg with controls Influenza 500 IP 1.87 Not ascertained PR8 50 [P 1.69 5 IP l.4l 500 PO -1 .07 50 PO 1 .21 .lap 305 50IP1n. 1.53 20 HC! 500 P0 2.5 3.2 50 P0 2.7 3.2 5 P0 2.0 3.2 Swine A 500 IP -1.8 14 50 I? 1.0 14 50 PO l.4 14 5 PO l.1 14

TEST NO. 3(INTRANASAL) Tests were performed to determine the efficacy against an Influenza virus of 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-ethy1- pyrazole (Compound A) administered intranasally to mice. The test compound was given in various concentrations and at various times before infection by aerosol with an appropriate dilution of the virus. The results obtained with a 10% suspension of the test compound as compared with those obtained with the diluent used for the suspension in mice infected with 25 multiples of the LD dose of the virus, are given below:

The results showed that the test compound exerted a definite protective effect at all times of administration. Between 40 and 70 percent of the animals survived the test period as compared to percent mortality in the untreated controls. The survival period of the treated animals that did die was increased to approximately twice that of the controls. Persistence of the effect was marked since no significant differences were seen between the results obtained with the various times of administration of the test compound.

A similar intranasal test conducted with various concentrations of 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-isopropylpyrazole (Compound D) in suspension administered 30 minutes before infection by aerosol with Influenza virus Jap 305 gave the following results:

Other tests were carried out to determine the inhibitory effect of 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-ethylpyrazole on various types of rhinovirus.

In each test two cultures of human embryonic lung were prepared of which one was treated with the above compound while the other served as control. The cultures were then infected with a strain of rhinovirus. The compound was used in concentrations of 50 and 75 gm/m1 and was considered to be active if the cytopathogenic effect of the rhinovirus was reduced by at least 75 percent as compared to the control culture. This cytopathogenic effect was determined by counting the number of plaques formed by destroyed cells.

Seven human types of rhinovirus were employed and the following results registered:

Rhinovirus Type Strain Activity active) A further series of tests was performed in which the inhibitory concentrations of 3-(4-pryidyl)-4-( 2-hydroxyphenyl)-5- ethylpyrazole against various human types of rhinovirus were determined by the gradient plate plaque-reduction technique. Cultures of HeLa cancer cells were used of which two were prepared for each test. One culture was treated with the above compound which was applied in gradient while the other culture served as control. Both cultures were then infected with a human type of rhinovirus. The inhibitory concentration was determined by measuring the zone of inhibition on the cellsheet. Six types of rhinovirus were employed and the following results registered.

With regard to viruses of the DNA group, tissue culture tests were performed to determine the activity of 3-(4- pyridyl )-4-( 2-hydroxyphenyl )-5-ethyl-pyrazole against Herpes Simplex. The test material employed was rabbit kidney tissue. In a test involving pretreatment of virus with the compound equal volumes of the compound and of the virus were incubated together in test-tubes for one hour at room temperature. This mixture was then inoculated into a bottle containing the rabbit kidney tissue. The bottle was incubated at 36 C. for 2 hours after which the fluids were discarded and 5 ml. of overlay added. After 4 days, the overlay was removed and crystal violet stain added for 5 minutes. The plaques appeared as clear areas in a blue background. A plaque-reduction of 50 percent was considered as significant. The same procedure was followed in a second test with the exception that the rabbit kidney tissue was first infected and the compound incorporated into the overlay. It was found that a dose of 250 pg caused 60 percent plaque-reduction in the first test and 100 percent plaque-reduction in the second test.

Another test was carried out with this same compound in order to evaluate its action against Herpes induced keratitis in the rabbit eye. The compound was used locally in concentrations of 2,1 and 0.5 percent and it was found that, at all three dosage levels, the compound inhibited the formation of geographic keratitic lesions as compared to the infected control animals.

Preliminary biological tests have indicated that compounds falling within the definition of formula I exert an effect against adenoviruses, parainfluenza virus and rhinoviruses.

The following Examples illustrate the preparation and formulation into pharmaceutical compositions of compounds in accordance with the invention.

EXAMPLE 1 Preparation of 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-ethylpyrazole and its hydrochloride.

In a 20liter three-necked reactor fitted with an ascending condenser, a dropping-funnel and a mechanical stirrer, were placed 1,455 g. (5.80 mol) OF 2-ethyl-3-isonicotinoylbenzofuran and 10 l. of isopropanol.

The resulting solution was stirred and 447 ml. of 98% hydrazine hydrate dissolved in 1,455 ml. of isopropanol were slowly added. During the operation, the temperature of the reaction medium gradually increased so as to reach 60 C. when all the hydrazine hydrate solution had been added. The solution was refluxed for 15 minutes and then allowed to cool to room temperature. The precipitate which formed was centrifuged out and washed with 500 ml. of isopropanol.

In this way a first fraction of 1,175 g. of 3-(4-pyridyl)-4-(2- hydroxyphenyl)-5-ethylpyrazole was obtained.

The isopropanol mother liquor was evaporated under vacuum until new crystals appeared, which were then centrifuged out and taken up in 2 liters of isopropanol. The suspension was centrifuged and a second fraction of 250g. of the desired product obtained.

The total amount of 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5- ethylpyrazole thus prepared was 1425 g. representing a yield of 92.8 percent M.p. 243244 C.

In the foregoing Example, ethanol or methanol may be used in place of the iospropanol and the end-product may be purified by crystallization from ethanol or methanol instead of from isopropanol.

To prepare the hydrochloride, 53 g. (0.2 mol) OF 3(4- pyridyl)-4-( 2-hydroxyphenyl)-5-ethypyrazole were suspended in 300 ml. of isopropanol. To this were added 20 ml. of concentrated hydrochloric acid (37 percent and 20 ml. of distilled water and the suspension heated until the pyrazole was completely dissolved. The hot solution was then passed through a filter and the filtrate allowed to cool while being slowly stirred. The hydrochloride crystals which formed were filtered out, washed over a filter with isopropanol and dried under vacuum. Yield: 51.8g. (86 percent). M.P. Decomposition at ca. 260 C.

By the same procedure as that described in the foregoing Example, the following compounds were prepared from the starting compound indicated:

From 2-methyl-3-isonicotinoyl-benzofuran M.p. C. 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-methylpyrazole M.p.260 C.

From 2-n-butyl-3-isonicotinoyl-benzofuran M.p.52 C. 3-( 4-pyridyl )-4-( 2-hydroxyphenyl )-5-n-butylpyrazole 238 C.

From 2-n-propyl-3-isonicotinoyl-benzofuran B.p. -150 C. /0.005 mm. Hg. 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-n-propylpyrazole M.p. 250 C. From M.p.450 C. 3-(4-pyridyl)-4-(Z-hydroxy-S-methoxyphenyl)-5-methylpyrazole M.p. 232 C.

From 2-ethyl-3-isonicotinoyl-5-chloro-benzofuran M.p. 98 C. 3-(4-pyridyl)-4-( 2-hydroxy-5-chlorophenyl)-5-ethylpyrazole M.p. 298 C.

2-methyl-3-isonicotinoyl-5-methoxy-benzofuran From 2-ethy1-3-isonicotinoyl-5-methyl-benzofuran M.p. (Hydrochloride) 170 C. (decomp.) 3-(4-pyridyl)-4-(2- EXAMPLE 2 Preparation of 2-methyl-3-( 4-pyridyl)-4-( 2-hydroxyphenyl) -5-ethylpyrazole In a one-liter flask fitted with an ascending condenser were placed 45 g. (0.18 mol) OF 2-ethyl-3-isonicotin-oylbenzofuran, 400 ml. of absolute ethanol and 27 g. of methylhydrazine. The solution was refluxed from hours and then allowed to cool at room temperature. The precipitate which formed was centrifuged, washed with a small quantity of absolute ethanol and dried under vacuum. The resulting product was recrystallized from absolute ethanol. In this way, 33.9 g. of 2-methyl-3- (4-pyridyl)-4-(2-hydroxyphenyl)-5-ethyl-pyrazole were obtained, melting at 236 C. Yield:68%.

To prepare the hydrochloride, 50 g. (0. l 8mol) of Z-methyl- 3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-ethylpyrazole were suspended in 250 ml. of isopropanol. To this were added 16.2 cc. of concentrated hydrochloric acid (37 percent) and the suspension heated until the pyrazole was completely dissolved. The hot solution was then passed through a filter and the filtrate allowed to cool while being slowly stirred. The hydrochloride crystals which formed were filtered out, washed over a filter with isopropanol and dried under vacuum. Yield: 45 g. (80.3 percent) M.p. Decomposition at ca. 230 C.

By the same procedure as that described in the foregoing Example, the following compounds were prepared from the starting compounds indicated: From 2-methyl-3-isonicotinoylbenzofuran M.p.80 C. and methylhydrazine 2,5-dimethyl-3-(4-pyridyl)-4-(2-hydroxypheny1)pyrazole M.p. 213 C. From 2-isopropyl-3-isonicotinoyl-benzofuran M.p. (HCl) 165 C. and methylhydrazine 2-methyl-3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-isopropy1- pyrazole M.p. 247 C. From 2-n-butyl-3-isonicotinoylbenzofuran M.p. 52 C. and methylhydrazine 2-methyl-3-(4pyridyl)-4-(2-hydroxyphenyl)-5-n-butylpyrazole M.p. 126 C. From 2-methyl-3-isonicotinoylbenzofuran M.p. 80 C. and ethylhydrazine; 2-ethyl-3-(4- pyridyl)-4-( 2-hydroxyphenyl) -5-methylpyrazole M.p. 158 C. From 2-ethyl-3-isonicotinoyl-benzofuran M.p. 58 C. and ethylhydrazine 2,5-diethy1-3-(4-pyridyl)-4-(2-hydroxyphenyl)-pyrazole M.p. 191C.

From 2-n-butyl-3-isonicotinoyl-benzofuran M.p. 52 C. and ethylhydrazine 2-ethyl-3-(4-pyridyl)-4-(2-hydroxyphenyl)-5- n-butylpyrazole M.p. 163 C. From 2-ethyl-3-isonicotinoylbenzofuran M.p. 58 C. and n-propylhydrazine 2-n-propyl-3- (4-pryidyl)-4-(2-hydroxyphenyl)-5-ethylpyrazole M.p. 175 C. From 2-methyl-5-isoniocotinoyl-benzofuran M.p. 80 C. and isopropylhydrazine 2-isopropyl-3-(4-pyridyl)-4-(2- hydroxyphenyl)-5-methylpyrazole M.p. 217 C. From 2-ethyl- 3-isoniocotinoyl-benzofuran M.p. 58 C. and isopropylhydrazine 2-isopropyl-3-(4-pryidy1)-4-(2-hydroxyphenyl)-5-ethylpyrazole M.p. 172 C.

From 2-isopropyl-3-isonicotinoyl-benzuforan M.p. 165 C. and isopropyl-hydrazine 2,5 diisopropyl-3-(4-pyridyl)-4-( 2-hydroxyphenyl )-pyrazole M.p. 177 C.

From Z-n-butyl-3-isonicotinoyl-benzofuran M.p. 52 C. and isopropylhydrazine 2-isopropyl-3-( 4-pyridyl )-4-( 2-hydroxyphenyl )-5-n-butylpyrazole M.p. 164 C.

(HCl) From 2-ethyl-3-isonicotinoyl-benzofuran M.p. 58 C. and nbutylhydrazine 2-n-butyl-3-(4-pryidy1)-4-(2-hydroxyphenyl)-5-ethylpyrazole M.p. 170 C.

From 2-isopropyl-3-isonicotinoyl-benzofuran M.p. (HCl) 165 C. and n-butylhydrazine.

2-n-butyl-3-(4-pyridyl)-4-( 2-hydroxyphenyl)-5-isopropylpyrazole M.p. 212 C.

From 2-n-butyl-3-isonicotinoyl-benzofuran M.p. 52 C. and nbutylhydrazine 2,5-di-n-butyl-3-(4-pyridyl)-4-(2-hydroxyphenyl)-pyrazole M.p. 121 0.

EXAMPLE 3 An ointment suitable for topical application was prepared in accordance with the known pharmaceutical techniques from the following ingredients:

3-(4-pyridyl)-4-( 2-hydroxyphenyl) -5-ethylpyrazole 2 g. Ointment base 98 g. 100

EXAMPLE 4 Suspensions for nasal instillation containing 5 and 10 percent w/v respectively of active compound were prepared in accordance with known pharmaceutical techniques from the following ingredients:

3-(4-pyridyl)-4-(2-hydroxyphenyl)-5-ethylpyrazole 5 g. 10g. Propylene glycol 5 g. 5g. Emulsion Antifoam AF 0. lg. 0. lg. Polyoxyethylene (20) sorbitan monooleate 0.1 g. 0.1 g. Methyl p-hydroxybenzoate 0.1g. 0.1g. Propyl p-hydroxybenzoate 0.0 l 5 g. 0.01 5 g. Methylcellulose (4000 cP.) 065g. 0.5g. Water (distilled) q.s. to give 100ml. 100ml.

The defoamer Emulsion Antifoam AF is a commercially available product marketed by Dow Coming and is stated to be a 30 percent silicone (simethicone) defoamer in a nonionic solution.

EXAMPLE 5.

A 1 percent solution for intranasal administration was prepared in accordance with known pharmaceutical techniques from the following ingredients:

3-(4 pyridyl)-4-(2-hydroxyphenyl)-5- ethylpyrazole hydrochloride lg. Water (distilled) q.s. to give 100 ml.

What is claimed is: 1. A pyrazole derivative having the general formula:

I X W151 \N/ ethyl, R is methyl and X is hydrogen.

9. A product in accordance with claim 1 in which R is ethyl, R is isopropyl and X is hydrogen.

10. A product in accordance with claim 1 in which R, is ethyl, R is n-butyl and X is hydrogen.

v UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 ,678,065 DATED July 18, 1972 INVENTOR(S) Fernand Binon and Jay Morton Bei le r It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: In the abstract,- column 1, l ines 20-25; and in claim 1, the formula OH H R /N R2 column 1, l ine B l, "5-isorpopyl" should read 5-isopropyl". Column 2, l Me 61, "5-ethhy-pyraz ole should read 5-ethyl pyrazol e",;- last table, 1 ines 67-71 (headings) Survival Dose Compound Route should read Com- I Dose Sun/Val mg/kg pound Route mg/kg S.

Column 5, 1 me 8 in table) "IP 50'' should read "IP 50 10 1.30"; l ines 23 2 i (headings) Dose Dose Compound Route should read Compound mg/kg Route mg kg Column t, i ines 6-8 (headings) Compound Virus Dose Compound Route should read Dose mg/kg Vi rus mg/kg Route UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 5,678,065 I DATED 1 Juiy18, 1972 r v Page 2) INVENTOR(S) Fernand Binon and Jay Morton Bei ier 7 It is certified that error appears in the abve-identified patent and that said LettersPatent are hereby corrected as shown below:

Column i, i ines 57-50 Time of ad- Agent ministration Survival Virus Dose before In- Muitipies fection Percent MDD S. I. of LD Compound 6 hr. 50 11,801.90 A i hr. 60 11,701.88 25 2 hr. 70 12 .802.07 25 min. iO 11.801.90 25 Diiuent 6 hr. 0 5.910.965 25 50 min. '0 .5.700.920 25 Virus 1 alone 0 6.20 25 should read 5 Time of Virus Dose AGENT Administration SURVIVAL Multiples before Infection Percent MDD S. I. of LD Compound 6 hr. 50 11.80 1.90 25 p A i hr. 11.70 1.88 25 2 hr. 12.80 2.07 25 50 min. +0 11.80 1.90 25 Diiuent 6 hr. 0 5.97 0.964 25 50 min. 0 5.70 0.920 25 Virus alone 0 6.20 25 iine 68 "of Doses should be No. of Doses" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION I PATENT NO. 1 3, 7 5 l DATED Jul y 18, 1972 I I Page 5) INVENTORG) I Fernand Binon and Jay Morton Bel ler It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, l ine 70, "M.p. 50C." should read "M.p. 5C.". Column 7, l ine 20, from 10 hours" should read "For 10 hours"; l ine 61, "2 methyl -5- i sonicotinoyl should read "2 -methyl 5- isonicotinoyl 1 v l I Signed and Scaled this v twenty-fifth Day of November 1975 {SEAN A Nest:

RUTH C. MASON mnmrlsxvhmvr f POHIIIS and Trademarks 

2. A product in accordance with claim 1 in which R1 is ethyl and R2 and X are hydrogen.
 3. A product in accordance with claim 1 in which R1 is methyl and R2 and X are hydrogen.
 4. A product in accordance with claim 1 in which R1 is n-propyl and R2 and X are hydrogen.
 5. A product in accordance with claim 1 in which R1 is isopropyl and R2 and X are hydrogen.
 6. A product in accordance with claim 1 in which R1 is n-butyl and R2 and X are hydrogen.
 7. A product in accordance with claim 1 in which R1 is methyl, R2 is hydrogen, and X is methoxy.
 8. A product in accordance with claim 1 in which R1 is ethyl, R2 is methyl and X is hydrogen.
 9. A product in accordance with claim 1 in which R1 is ethyl, R2 is isopropyl and X is hydrogen.
 10. A product in accordance with claim 1 in which R1 is ethyl, R2 is n-butyl and X is hydrogen. 